This year's declassified Belfast files chart the final decline of former shipbuilding giant Harland and Wolff. They show that in 1987, faced by mounting losses and missed deadlines, then secretary of state Tom King recommended closing the yard.

At the same time, however, a confidential Northern Ireland Office (NIO) memo warned of serious unrest in the Protestant community if the 3,000-strong workforce was paid off.

The problems at the yard surfaced in a memo from DJ Watkins of the NIO to David Fell of Stormont’s Department of Economic Development on June 24th, 1987. The official reported that the secretary of state “was deeply disturbed to hear your report of increased cash difficulties” at the company.

King understood that it was in need of £10 million and wanted to know why this need had not been identified earlier.

Moves to shut down the Belfast shipyard elicited a plaintive memo from FG McConnell of the NIO to King on September 9th, 1987. This warned of the political implications of any closure of the shipyard in view of its symbolic significance.

He added: “The closure of H/W would be perceived as an act of betrayal” and “a further step towards withdrawal from the province . . . It is likely that this mood would be exploited by loyalist paramilitaries.”

In the event, the yard was not closed, thanks to a management-and-employee buyout in partnership with Norwegian shipping magnate Fred Olsen. Shipbuilding finally ceased at Harland and Wolff in 2003.